By Okhoo Hanes, U. C. Master Gardener of Napa County
The olive tree (Olea europaea) is well suited to Napa Valley. The tree's Mediterranean origin makes it a natural fit for our sunny, arid and temperate climate. Our warm summers encourage fruit growth, and winter provides the necessary 200 to 300 chill hours (hours under 45°F). The olive tree is frost-resistant, withstanding temperatures down to 15°F.
Rich soil and fertilization improve fruit yield, but the olive tree tolerates poor soil. Deer do not like olive leaves, fortunately, as many a plant in the Napa Valley succumbs to their voracious appetite.
Once established, olive trees require little or no water. Still, deep watering every other week in a hot summer results in better fruit production and helps sustain the tree during drought years. Generally, a rainy winter will almost fulfill the tree's annual watering needs, unless your objective is a good fruit crop.
Extreme weather does not appear to affect olive trees drastically. Even so, growing olive trees in the Napa Valley is not entirely trouble-free.
The olive tree can be grown for both culinary and ornamental purposes. Raw olives are not edible but you can cure them or press them for oil. Branches make beautiful wreathes. In landscaping, the silvery-green olive tree contrasts nicely with dark green redwood trees and the brighter greens of oaks.
The olive tree is evergreen, low care and drought tolerant. Due to this generally unfussy habit, it makes a suitable accent patio container tree, a privacy screen or even a hedge. Dwarf varieties tend to reach six to eight feet in height, adequate for a hedge. But standard varieties can reach 30 feet in height and width. With close spacing and systematic pruning, they can create a tall, dense barrier. Olive trees in containers will need regularly watering to maintain moisture levels due to their limited root zones.
If you are growing olive trees purely for ornamental or hedging purposes, consider a fruitless variety. Then you can avoid the hassle of harvesting or cleaning up fallen fruit, the patio staining caused by dropped fruit and the necessity to spray for olive fruit fly. Fruitless varieties include Swan Hill, Majestic Beauty, Wilsonii, Bonita and Little Ollie, a dwarf type topping out at about eight feet. Although Swan Hill produces neither pollen nor fruit, other fruitless varieties may produce tiny flowers and fruit occasionally.
If you would like to cure olives, you can find a detailed recipe online from the University of California Cooperative Extension (http://anrcatalog.ucanr.edu/Details.aspx?itemNo=8267 ). Or plan to attend the U. C. Master Gardeners of Napa County food-preservation workshop on July 27 (details below).
If you would like to press your olives for oil, some commercial facilities such as Jacuzzi Winery in Sonoma accommodate home growers with small production by aggregating the fruit for pressing. For current information about local olive-mill options, contact the Master Gardener office.
Popular olive varieties for oil include Arbequina, Mission, Manzanillo, Sevillano and Frantoio.
Depending on the variety and when the olives are picked, the oil can range in flavor from peppery to buttery. Before planting olive trees for oil, educate yourself about the flavor differences. Many wineries that grow olives offer olive oil tastings and many specialty-food markets carry varietal olive oils.
Olive fruit fly is the most common pest of olive trees in the Napa Valley. It lays its eggs in the fruit, rendering the olives unusable. Do not add damaged fruit to your compost pile; discard the olives in a brown yard-waste bin. The fly was first found in Napa in 2001 and is now ubiquitous throughout the county. Preventing or minimizing the infestation is critical to slowing its spread.
If you have fruiting olive trees but don't care about harvesting the fruit, spray trees with a plant growth regulator containing ethephon (available in many nurseries) in May or June to prevent fruit set. Alternatively, water the trees with a high-pressure hose during flowering. If your trees do produce damaged fruit, harvest it and discard it. Be sure to pick up any fruit on the ground as well.
If you do want the fruit, spray trees with Spinosad, an organic control, following manufacturer's directions. Harvest early in November and pick up all fallen fruit.
The University of California website has excellent information on growing olives in the home garden. (http://homeorchard.ucanr.edu/Fruits_&_Nuts/Olive/). Paul Vossen, an olive authority and former UC farm advisor for Marin and Sonoma Counties, produced a detailed slide presentation on olive cultivation, titled “Olive as a New Crop” (http://cesonoma.ucanr.edu/files/27719.pdf). Although intended for commercial producers, the presentation's content should be of great interest and usefulness to home gardeners as well.
Workshops: U. C. Master Gardeners of Napa County will hold a workshop on “Growing Olives” on Saturday, July 14, from 9:30 a.m. to 11:30 a.m. Location will be provided after registration. Would you like an olive tree or two in your garden? Olive trees are an attractive evergreen and can provide fruit when properly cared for. Learn what to do in every season to have a healthy tree and tasty harvest. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
U. C. Master Gardeners of Napa County will hold a workshop on “Freezing and Dehydrating” on Saturday, July 21, from 9:30 a.m. to 11:30 a.m., at Napa Farmers Market, 195 Gasser Drive, Napa. Freezing and dehydrating are ways to preserve your summer bounty in its prime, whether you have too much ripe at once or simply want to get a head start on stocking up for winter. Join UC Master Gardeners as they discuss the benefits of each method and some different ideas for snacks and pantry staples. The workshop is free but registration is required. Online registration.
U. C. Master Gardeners of Napa County will hold a workshop on “Basic Food Preserving” on Saturday, July 27, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Canning, freezing and drying are among the most basic food preserving methods. It is important to practice safe methods and to stay up-to-date with the most reliable d information about food safety. Master Food Preservers will discuss each process, the equipment required and hazards to avoid, and give demonstrations and recipes. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4221, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
![ANR Pub 8267 Olives, Safe Methods ANR Pub 8267 Olives, Safe Methods](/blogs/blogcore/blogfiles/54050.png)
![Olive varieties (UC Cooperative Extension) Olive varieties (UC Cooperative Extension)](/blogs/blogcore/blogfiles/54045.jpg)
![The Backyard Orchard, Olives The Backyard Orchard, Olives](/blogs/blogcore/blogfiles/54049.png)
![Intro Paul Vossen Olive PPT Intro Paul Vossen Olive PPT](/blogs/blogcore/blogfiles/54048.png)
- Author: Ben Faber
SACRAMENTO — A portion of Los Angeles County has been placed under quarantine for the Oriental fruit fly following the detection of nine flies in the Hollywood area. The quarantine zone measures 75 square miles. A link to the quarantine map may be found here:https://www.cdfa.ca.gov/plant/off/regulation.html
“California's fruit fly season extends from late summer through the fall,” said California Agriculture Secretary Karen Ross. “These pests like Southern California for some of the same reasons other travelers do: the pleasant climate and the tremendous variety of food. Fortunately, with the help of local residents, we have a great track record of eradicating these infestations.”
To prevent the spread of fruit flies through homegrown fruits and vegetables, residents living in the fruit fly quarantine area are urged to not move any fruits or vegetables from their property. Produce may be consumed or processed (i.e. juiced, frozen, cooked, or ground in the garbage disposal) at the property where it was picked.
The most common pathway for these pests to enter the state is by “hitchhiking” in fruits and vegetables brought back illegally by travelers as they return from infested regions around the world or from packages sent to California. To help prevent infestations statewide, officials asks residents to refrain from bringing or mailing fresh fruit, vegetables, plants, and soil into California unless agricultural inspectors have cleared the shipment beforehand.
While fruit flies and other invasive species threaten California's crops, the vast majority of them are detected in urban and suburban areas.
“That's why it's important for residents to cooperate with quarantine restrictions and allow authorized agricultural workers access to properties to inspect fruit and oriental fruit fly traps for signs of an infestation,” said Secretary Ross.
Following the principles of Integrated Pest Management (IPM), the California Department of Food and Agriculture (CDFA) uses a “male attractant” technique in its eradication effort for this pest. This approach, which has successfully eliminated dozens of fruit fly infestations in California, significantly reduces the amount of insecticide required to eradicate the population, and only targets the fruit flies – no other insects or animals are harmed. The treatment program is being carried out over several square miles surrounding the sites where the oriental fruit flies were trapped.
The oriental fruit fly is known to target more than 230 different fruits, vegetables, and plants. Damage occurs when the female fruit fly lays her eggs inside the fruit. The eggs hatch into maggots and tunnel through the flesh of the fruit, making it unfit for consumption.
The oriental fruit fly is widespread throughout much of the mainland of Southern Asia and neighboring islands including Sri Lanka and Taiwan, and has invaded other areas, most notably Africa and Hawaii.
Residents with questions about the quarantine may call the CDFA Pest Hotline at 1-800-491-1899.
—California Department of Food and Agriculture
Photos: OFF adults and Grapefruit infested with larvae of oriental fruit fly, Dacus dorsalis.
![oriental fruit fly image oriental fruit fly image](/blogs/blogcore/blogfiles/46050.jpg)
![oreintal fruit fly citrus oreintal fruit fly citrus](/blogs/blogcore/blogfiles/46051.jpg)
Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa
Help Desk Response: The spotted wing drosophila (Drosophila suzukii) is a relatively new pest of cherries and other soft fleshy fruits (strawberries, raspberries, blackberries, blueberries, etc). Unlike other vinegar flies that attack rotting or fermenting fruit, the spotted wing attacks maturing fruit. The name spotted wing drosophila comes from the single black spot at the tip of each wing of the male adult. Don't think though that you will be able to identify this fly by those markings without magnification because these adults are small, really small. The female is able to penetrate the skin of the fruit to lay her eggs and this act creates a small depression (“sting”) on the fruit surface. The eggs hatch and the maggots develop and feed inside the fruit, causing the flesh of the fruit to turn brown and soft.
An alternative to malathion with fewer negative environmental effects would be spinosad (e.g., Monterey Garden Insect Spray and see http://www.ipm.ucdavis.edu/TOOLS/PNAI/pnaishow.php?id=65); h
Since spotted wing drosophila attacks ripening fruit it is often not noticed in home garden situations until the fruit is being harvested. Sprays at this time will not protect the crop because maggots are already in the fruit. If only some of the fruit are infested, you can salvage some of the crop by harvesting immediately and sorting the fruit, removing any with “stings” on the surface. It is recommended that all infested fruit be removed from the tree and picked up from the ground. It should then be placed in a sealed plastic bag and disposed of in the trash or buried. Do not put the infested fruit in your compost pile as it may not get hot enough to destroy the eggs and larvae still in the fruit.
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This blog was originally written by Emma Connery, Retired Master Gardener Program Coordinator, for publication in the Contra Costa Times April 2, 2011. Slight changes have been made to the original for this blog and are the full responsibility of the blog editor.
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Help Desk of the UC Master Gardener Program of Contra Costa County
Come to the UC MGCC Program's Great Tomato Plant Sale
Walnut Creek 4/2&9, Richmond 4/9, and Antioch 4/16
Click for locations and plant lists!
Dozens of heirloom tomatoes & vegetables chosen especially for Contra Costa
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).
- Author: Mark Bolda
Esta oficina ha tratado de varios pedidos de información de la drosófila de alas manchadas en moras y fresas, sobre todo de ranchos de escala pequeña, y estos en su mayoría granjas certificadas para producción orgánica.
Vamos a hacer un repaso breve en la mejor manera de manejar drosófila de alas manchadas en estos casos de ranchos pequeños manejados en una manera orgánica:
Uno debe dirigirse a este problema en dos maneras. La primera es usar el insecticida Entrust (ingrediente activo spinosad) como una aplicación a aspersión es recomendado a la misma vez, a la medida de lo posible, uno va removiendo las frutas malformadas, viejas y podridas del campo y echándolas fuera del campo sino en un basurero en un pozo excavado de la tierra. Puede ser útil para productores de fresa aplastar la fruta echada en el surco con un paso del tractor para fomentar el reseco rápido de la fruta y eliminar pronto la posibilidad de la larva de éste peste a cumplir su ciclo de vida. Entonces el insecticida aplicado está reduciendo el número de adultos de este mosco, a la misma vez que todas las vías de aumento de población se vaya eliminando. Fruta buena se cosecha y vende, fruta mala se remueve y destruye, así que no sobra la posibilidad de cumplir su ciclo de vida y tornarse a más moscos.
Aunque lo descrito arriba parezca muy bien, dos años de investigaciones en el campo nos informa que el removimiento de la fruta del campo solo no va a ser suficiente de bajar las poblaciones de la drosófila de alas manchadas a niveles aceptables. Siempre habrá una fruta que falto de ser cosechada y esa fruta misma servirá a apestar una vez más el campo. Por este hecho siempre el programa recomendado de controlar el mosco es aplicar insecticida junto con las prácticas de sanitación.
La última palabra es darse cuenta de lo que está pasando en el alrededor de su campo de producción. ¿Hay lugares de poblaciones no controladas a lado o arbustos de zarzamora silvestre? Ambas áreas sirven como hospederas de drosófila de alas manchadas y le benéfica a Ud. obtener un cierto nivel de control allí también.
Se menciona el uso de un pesticida en este artículo. Como siempre, antes de usar cualquier pesticida, consulte la etiqueta para direcciones en su uso correcto.
![Macho de drosófila de alas manchadas. Macho de drosófila de alas manchadas.](/blogs/blogcore/blogfiles/24720.jpg)